Tube expansion tool



1965 a-a. E. LINTHICUM ETAL 3,221,523

TUBE EXPANS ION TOOL Filed Aug. 17, 1962 fiiqaaqq a qqq qqq T 2 wm mm mmmm x mm 2 0m IN VENTOR.

ATTORNEY.

United States Patent 3,221,528 TUBE EXPANSION TOOL Harley E. Linthicumand William A. Linthicum, Springfield, ()hio., assignors to CarrierCorporation, Syracuse, N.Y., a corporation of Delaware Filed Aug. 17,1962, Ser. No. 217,747 5 Claims. (Cl. 72-122) This invention relatesgenerally to tube expansion devices. More particularly, this inventionrelates to a tool for radially expanding a portion of a tubular memberfor the purpose of uniting it with a structural part having a preformedaperture for receiving the tube.

Tools of the type to which this invention relates are employed for thepurpose of expanding with a roller action the ends of tubular membersinto tube support sheets as, for illustration, in heat exchangeequipment. The portion of the tube to be united with the tube sheet isexpanded in a radial direction into tight mechanical connection with thewall surrounding an aperture in the support sheet for receiving thetube. The action employed in causing the union between the tube and thesheet is referred to as tube rolling and is accomplished by forcing aseries of roller elements outward against the inner surface of the tubeby a mandrel member constructed so that the outward movement of therollers is controlled.

When it is desired to unite relatively small diameter, thin wall tubeswith tube support sheets, the power requirement of the tool, representedby the torque necessary to force the tubular member outward, is at aminimum. It has been discovered that under these conditions the housingaccommodating the roller elements usually referred to as the cage, maybe connected directly to the power source so as to be rotated therewith.Normally, the mandrel member is connected to the power source and isrotated thereby.

Accordingly, to chief object of this invention is the provision of atool of the kind described wherein the cage member housing the rollerelements is connected directly with the source of power providing rotarymotion of the type necessary to impart rotational motion to the rollerelements assembled within the housing. With such an arrangement themandrel is freely rotatable within the housing and may be advanced bythe action of the roller elements when the tool engages the work.

An additional object of the invention is the provision of an improvedtool of the kind contemplated, wherein, the mandrel member is normallyarranged within the housing accommodating the roller elements in such amanner that movement of the mandrel in the housing necessary to producethe rolling force is accomplished against the action of the spring. Thisarrangement has the advantage of causing prompt retraction of themandrel into the housing at the conclusion of use.

A further object of the invention is the provision of a tool forexpanding tubes in which there are means provided for yieldablyadjusting the position of the mandrel within the housing so that acontrolled amount of outward movement of the roller elements may takeplace prior to the engagement of the tool with the work.

A still further object of the invention is the provision of a novelmethod of uniting a tubular member and a structural support part whereinrotational motion is provided directly to the housing under thecircumstances where the roller elements will pick up and advance themandrel longitudinally of the housing against the action of theresilient spring member.

These and other objects of the invention will be apparent uponconsideration of the ensuing specification and drawings in which:

3,221,528 Patented Dec. 7, 1965 FIGURE 1 is an elevational view, partlyin section, illustrating a tool constructed in accordance with thisinvention; and

FIGURE 2 is a fragmentary view illustrating the action of the rollerelements as they engage the work.

Referring more particularly to the drawings for an illustration of apreferred embodiment of the invention, there is shown a roller supportmember 10 serving as a housing for the operating parts of the tool whichis provided with a diiferential passage 12 extending there through. Theportion 14 of the passage 12 shown to the right of the tool is providedwith the largest diameter and is threaded for a purpose to be laterdescribed. Passage 12 through the roller support member includes asection 16 of intermediate diameter and a section 18 of a smallerdiameter, the latter two sections being defined by shoulder 20.

At the end of the roller support member 10 remote from the portion 14,there is provided a plurality of circumferentially spaced slots 22arranged in a skewed direction relative to the longitudinal axis ofmember 10. Disposed in each slot 22 is a roller elem-ent 24.

Assembled within the roller support member serving as the housing is amandrel 26. The mandrel includes a first tapered end portion 28 whichterminates in a portion 30 of constant diameter. Located axiallyadjacent portion 30 is an intermediate portion or section 32 having arelieved configuration for a purpose to be later described. End section34 of a diameter similar to the portion 30 completes the mandrel whichis provided with a cap 36 arranged to snugly engage bushing 37 arrangedin portion 16 of the passage through the roller support memher.

A spring 38 is arranged so as to engage the shoulder 20 and the bushing37 for the purpose of urging the mandrel to its retracted position shownin the drawing. An adjustable abutment member 40 is threadably mountedwithin section 14 of passage 12 for the purpose of adjusting theposition of the mandrel relative to the rollers against the action ofthe spring 38.

Considering the operation of the tool forming the invention, with thetool penetrating the open end of the tube, adjustable abutment member 40is manipulated so that the mandrel 26 forces the roller elements 24 intoengagement with the inner surface of the tube, see enlarged FIGURE 2, asit rests in the opening in the sheet to which it is to be joined. Theend of the tool having the threaded surface 14 is connected to asuitable power source which then supplies rotary motion directly to theroller support member 10.

With the parts in engagement as described, the member 10 is rotatedcarrying the rollers 24 with it. As indicated above the rollers 24 arearranged at an angle to the longitudinal axis of the member 10. Underthe circircumstances the member 10 will tend to travel through the tubeas the assembly becomes self-feeding. This movement may be restrained bythe operator should he desire. The action of the rollers arranged asthey are relative to the end 28 of the mandrel causes the mandrel toadvance from the housing against the action of spring 38. This latteraction is accomplished as the skewed rollers 24 rotate about theirlongitudinal axis in a manner known in the art. With the constructionshown the rollers 24 rotate as a unit with the member 10 and at the sametime rotate individually about their own axis, thus self-feeding of themandrel ensues.

The advance of the mandrel provides a camming action forcing the rollerelements into engagement with the inner surface of the tube to deform itinto a tight bond with the surface of the support member defined by theopening accommodating the tube.

Travel of the mandrel continues until the section 32 of the mandrel isin registry or alignment with the rollers 24. At this point, the rollersdrop inwardly and the rolling action is terminated. The operator thenwithdraws the assembly from the work and the action of the spring 38retracts the mandrel to the position illustrated in the drawing.

With the assembly shown, the member 10, sometimes referred to in the artas the cage, is rotated directly by its connection with the powersource. Due to tube wall variations, the tube I.D. becomes a variable.For proper action the tool should engage with the unrolled tube I.D.somewhere between the front end of the roll and center (lengthwise).This can be assured by adjusting position of element 40 which in turn,positions mandrel 28 relative to rollers 24. With the constructiondescribed the tool action is rapid and precise resulting in considerableeconomy of operation. The enlargement of the tube is limited by theconfiguration of the parts and the positioning of the mandrel section 28relative to the roller elements accurately determined and maintained bythe action of spring 38 and abutment member 40.

The above disclosure has been given by Way of illustration andelucidation, and not by way of limitation, and it is desired to protectall embodiments of the herein disclosed inventive concept within thescope of the appended claims.

We claim:

1. A tool for expanding a tubular member into engagement with a supporthaving an opening for receiving said tubular member comprising:

elongated roller support means having roller accommodating slotscircumferentially arranged therein; roller means disposed in said rollersupport means;

a mandrel slidably mounted within said roller support means;

spring means engaging with and yieldably adjusting the mandrel relativeto the rollers so that motion imparted to the roller support means, asradial movement of the rollers is resisted, will advance the mandrellongitudinally of said rollers.

2. The tool set forth in claim 1 wherein said mandrel includes a portionof reduced dimension into which said rollers drop to limit thelongitudinal advance of the mandrel relative to the rollers.

3. The tool set forth in claim 1 wherein said mandrel is provided with atapered end portion and an intermediate portion spaced therefrom ofreduced thickness.

4. The tool set forth in claim 1 wherein said means for yieldablyadjusting the mandrel includes a spring and stop member for varying theaction of the spring and adjustment of the mandrel.

5. A tool for imparting limited radial expansion throughout apredetermined axial portion of a hollow structural member for thepurpose of uniting the member with a second structural member having anopening for receiving the first member comprising a hollow elongatedcage member of substantial axial extent having a plurality of slotscircumferentially spaced about a first end theerof, said slots beingarranged in a direction skewed with respect to the axis of the cagemember, said cage member being further provided with a passage of adifferential diameter extending therethrough;

a plurality of rollers mounted in said cage member so that each slotaccommodates one roller therein;

a mandrel having a tapered end portion, an enlarged end portion and arelieved intermediate portion spaced from each end slidably mounted insaid cage member passage;

spring means assembled within a portion of the cage member passage ofconstant diameter with one end in engagement with the enlarged endportion of the mandrel and the other end in engagement with a shoulderdefined by the juncture of two portions of the cage member passagehaving different diameters;

an adjustable abutment member mounted in said passage in engagement withsaid mandrel member, said abutment member being operable to yieldablyadvance said mandrel through said passage until predetermined engagementbetween said tapered mandrel end and said rollers is effected so thatwhen the assembly is inserted Within a part to be expanded in a radialdirection and the rollers restrainably engage the part and the mandrel,rotary motion imparted to the cage member causes the rollers to advancethe mandrel while simultaneously exerting a continuing outwardlydirected force against the tube until the section of the mandrel havingthe relieved portion is aligned with said rollers.

References Gited by the Examiner UNITED STATES PATENTS 1,921,810 8/1933Duchesne 153-82 2,045,787 6/1936 Maupin 153-82 2,754,577 7/1956 Maxwell29-523 2,817,385 12/1957 Benjamin 153-82 3,047,045 7/1962 Baker 153-823,188,850 6/1965 Linthicum 72-393 CHARLES W. LANHAM, Primary Examiner.

5. A TOOL FOR IMPARTING LIMITED RADIAL EXPANSION THROUGHOUT APREDETERMINED AXIAL PORTION OF A HOLLOW STRUCTURAL MEMBER FOR THEPURPOSE OF UNITING THE MEMBER WITH A SECOND STRUCTURAL MEMBER HAVING ANOPENING FOR RECEIVING THE FIRST MEMBER COMPRISING A HOLLOW ELONGATEDCAGE MEMBER OF SUBSTANTIAL AXIAL EXTENT HAVING A PLURALITY OF SLOTSCIRCUMFERENTIALLY SPACED ABOUT A FIRST END THEREOF, SAID SLOTS BEINGARRANGED IN A DIRECTION SKEWED WITH RESPECT TO THE AXIS OF THE CAGEMEMBER, SAID CAGE MEMBER BEING FURTHER PROVIDED WITH A PASSAGE OF ADIFFERENTIAL DIAMETER EXTENDING THERETHROUGH; A PLURALITY OF ROLLERSMOUNTED IN SAID CAGE MEMBER SO THAT EACH SLOT ACCOMMODATES ONE ROLLERTHEREIN; A MANDREL HAVING A TAPERED END PORTION, AN ENLARGED END PORTIONAND A RELIEVED INTERMEDIATE PORTION SPACED FROM EACH END SLIDABLYMOUNTED IN SAID CAGE MEMBER PASSAGE; SPRING MEANS ASSEMBLED WITHIN APORTION OF THE CAGE MEMBER PASSAGE OF CONSTANT DIAMETER WITH ONE END INENGAGEMENT WITH THE ENLARGED END PORTION OF THE MANDREL AND THE OTHEREND IN ENGAGEMENT WITH A SHOULDER DEFINED BY THE JUNCTURE OF TWOPORTIONS OF THE CAGE MEMBER PASSAGE HAVING DIFFERENT DIAMETERS; ANADJUSTABLE ABUTMENT MEMBER MOUNTED IN SAID PASSAGE IN ENGAGEMENT WITHSAID MANDREL MEMBER, SAID ABUTMENT MEMBER BEING OPERABLE TO YIELDABLYADVANCE SAID MANDREL THROUGH SAID PASSAGE UNTIL PREDETERMINED ENGAGEMENTBETWEEN SAID TAPERED MANDREL END AND SAID ROLLERS IS EFFECTED SO THATWHEN THE ASSEMBLY IS INSERTED WITHIN A PART TO BE EXPANDED IN A RADIALDIRECTION AND THE ROLLERS RESTRAINABLY ENGAGE THE PART AND THE MANDREL,ROTARY MOTION IMPARTED TO THE CAGE MEMBER CAUSES THE ROLLERS TO ADVANCETHE MANDREL WHILE SIMULTANEOUSLY EXERTING A CONTINUING OUTWARDLYDIRECTED FORCE AGAINST THE TUBE UNTIL THE SECTION OF THE MANDREL HAVINGTHE RELIEVED PORTION IS ALIGNED WITH SAID ROLLERS.